This revised application proposes a five-year research program for the Mentored Research Scientist Development Award (K01) from the National Institute on Drug Abuse for Kathryn E. McCollister, Ph.D. Dr. McCollister is an ideal candidate for this award given her dual interest in health economics and substance abuse research, the solid infrastructure available to her at the University of Miami, and the exceptional group of collaborators that have agreed to work on this project. The intent of the proposed training and research is to focus on Dr. McCollister's development as a health economist, to establish a strong research program in the area of economic evaluation of substance abuse treatment in criminal justice settings, and achieve important scientific accomplishments in the areas of grant writing, technical presentations, and peer reviewed publications. Dr. McCollister will work collaboratively with her primary mentor, Michael T. French, Ph.D., and a team of multidisciplinary scientists to examine the economic impact of substance abuse treatment in criminal justice settings. Programs in California, Delaware, Colorado, and Kentucky will provide cost and outcome data for the economic analyses. Dr. McCollister's research will incorporate examinations of program methodology, alternative treatment approaches, program evaluation instruments, and statistical modeling to establish a benchmark approach for estimating cost and benefits of corrections-based drug abuse treatment programs. The primary research objective is to provide an economic perspective on the decision to fund prison-based treatment as well as further justification for including a transitional aftercare component in corrections-based addiction interventions. This research will provide the foundation for developing future grant proposals related to the economics of addiction and criminal justice policy. The main outcomes of this Mentored Research Scientist Development Award are (1) advanced health economics and econometrics training for Dr. McCollister, (2) multidisciplinary research on substance abuse treatment in criminal justice settings, (3) conference presentations on research findings, (4) several publications in peer-reviewed professional journals, and (5) the development of future grant applications to support continued economic research of substance abuse interventions in criminal justice settings.